The present invention relates to an electronic component and a structure of terminals thereof and, more particularly, to an electronic component (e.g., a central processing unit (CPU) slot) capable of forming electric connection with circuits on some devices (e.g., computer motherboards) so as to plug with corresponding electronic products (e.g., CPUs) having a plurality of pins. The present invention is characterized in that tin balls can be fixed at predetermined positions without passing through a tin oven, and tin material of the tin balls will not spread upwards when being soldered onto a circuit board. Thereby, nickel can be coated on terminals to prevent tin from spreading upwards, and the heights of the tin balls will be in agreement to facilitate soldering with a circuit board.
When electronic products having a plurality of pins are to form electric connection with some devices, electronic components having a plurality of insertion holes (corresponding to the above pins) are generally used. For example, a CPU (an electronic product) having a plurality of pins forms electric connection with a computer motherboard by inserting into a CPU slot (an electronic component).
As shown in FIG. 2, a prior art electronic component 200 comprises a plurality of terminals 1 and a plastic main body 2 having a plurality of corresponding open terminal passageways 21.
Please refer to FIG. 1. Two sides of a main body portion11 of the terminal 1 are extended to form two symmetric elastic contact pieces 14 to clamp a pin (not shown) of an electronic product. The distal end of the terminal 1 is a pin portion 13 for soldering. A bearing portion 12 is between the main body portion 11 and the pin portion 13. The bearing portion 12 and the pin portion 13 form a terminal pin.
Please refer to FIGS. 1 and 2. The terminal 1 of the conventional electronic component 200 is first bent to let the pin portion 13 be transversal so as to facilitate soldering with a tin ball 15. Before being soldered to the tin ball 15, the terminal 1 with the bent pin portion 13 is installed in the terminal passageway 21 of the plastic main body 2, as shown in FIG. 2. In order to join the tin ball 15 at the bottom face of the pin portion 13 of each of the terminals 1, it is necessary to place the above electronic component 200 upside down and paste soldering-assistant agent on the bottom face of the pin portion 13 of each of the terminals 1. When the electronic component 200 passes through a tin oven, the tin balls 15 placed on the pin portions 13 (as shown in FIG. 3) can be soldered onto the bottom faces of the pin portions 13 of the terminals 1 so as to be soldered to a circuit board (not shown).
For the conventional electronic component 200, when performing the procedures of placing the electronic component upside down, pasting on tin glue, and then passing through the tin oven, it is generally necessary to coat gold, nickel, and tin on the upper, middle, and lower sections of the terminals 1, respectively. The nickel is exploited to prevent tin from spreading to the main body portion 11 or even to the elastic contact pieces 14. However, because the original terminal 1 is too short, the length thereof will be even shorter (about 2-2.5 mm) after the pin portion 13 thereof is bent. It thus is very difficult to respectively coat gold, nickel, and tin. Therefore, the present practice is to totally coat gold. But the tin balls at the bottom end will spread upwards along the terminals 1 coated with gold when they start melting. In addition to the reason that there is no nickel for blockade, there is one reason that the terminal passageways are open so that tin can spread upwards without any blockade.
As shown in FIG. 4, when the tin ball 15 is to be soldered onto the bottom face of the pin portion 13 of each of the terminals 1, the whole terminal 1 will be covered by tin if the temperature control is somewhat improper. The tin ball originally reserved for soldering with a circuit board will thus be drawn away or even disappear. Moreover, because the degree of being drawn away of each tin ball is different, the height of each tin ball will vary so that the bottom face of the electronic component 200 will be uneven. Therefore, it is difficult to place the electronic component 200 onto a circuit board (not shown) for performing soldering.
The above conventional electronic component 200 has the following drawbacks.
1. After finishing the manufacturing of the electronic component 200, it is also necessary to let it pass through a tin oven for fixedly soldering the tin balls 15 onto the bottom ends of the terminals 1 at the bottom end of the electronic component 200.
2. Because the terminal 1 is too short, it is very difficult to coat nickel for blocking tin. Therefore, the tin material will easily spread upwards to the whole terminal 1 or even contaminate the elastic contact pieces 14 when the electronic component passes through a tin oven.
3. The heights of the tin balls 15 at the bottom side of the finished electronic component 200 are different so that it is very difficult to place the electronic component on a circuit board for performing soldering. Moreover, the soldered circuit will be uneven.
Accordingly, the primary object of the present invention is to provide an electronic component and a structure of terminals thereof. After the electronic component is manufactured, tin balls can be clamped at the bottom end of the electronic component without passing through a tin oven. Besides the tin balls can contact the terminals, the bottom ends thereof are exposed to be soldered to a circuit board. Therefore, the tin balls at the bottom side of the electronic component can be fixed without passing through a tin oven. The length of the terminal is sufficient to be respectively coated with gold, nickel, and tin so as to prevent tin from spreading upwards. Moreover, the heights of the tin balls are in agreement to facilitate soldering with a circuit board and let the soldered circuit board be even.
Another object of the present invention is to provide an electronic component and a structure of terminals thereof, whereby tin balls will not fall off when being pressed into the plastic main body.
Yet another object of the present invention is to provide an electronic component and a structure of terminals thereof, whereby good contact effect can be achieved between tin balls and the terminals.
To achieve the above objects, the present invention provides an electronic component and a structure of terminals thereof. The electronic component comprises a plurality of terminals and a plastic main body having a plurality of terminal passageways. A pin portion of the terminal protrudes downwards out of one of the terminal passageways. The pin portion has also a catching portion of through hole type. The bottom end of the terminal passageway forms a bottom receiving room for receiving a tin ball. After the pin portion of the terminal is bent, the catching portion thereof can catch it from below the tin ball. Because the tin balls have been caught and positioned by the catching portions of the pin portions of the terminals, the tin balls at the bottom side of the electronic component can be fixed without passing through a tin oven. Because of the lengthened pin portion, the length of the whole terminal is sufficient to be respectively coated with gold, nickel, and tin for preventing tin from spreading upwards. Because the tin balls do not pass through a tin oven, the heights thereof can be kept in agreement so that the electronic component can evenly contact a circuit board when it is placed on the circuit board for soldering. Moreover, because the tin material of the tin balls will not spread upwards, the soldered circuit board will be even.
Secondly, the depth of the bottom receiving room at the bottom end of the plastic main body is just larger than the radius of the implanted tin ball, and the bore thereof is just smaller than the diameter of the implanted tin ball. The tin ball is thus fixed by the bottom receiving room in pressing-in way. It is very difficult to take out the tin ball in reverse direction, not mentioning that the tin ball falls off.
Thirdly, the terminal passageway of the plastic main body has a base with one open side. The bottom end of the terminal passageway has the bottom receiving room separated by the base. After the terminal is installed into the terminal passageway, the pin portion of the terminal and a bearing portion between the main body portion and the pin portion will pass through the open side of the terminal passageway so that the bearing portion of the terminal becomes one wall of the bottom receiving room. After the tin ball is pressed into the bottom receiving room and fixed, it can contact the bearing portion of the terminal. Furthermore, because the catching portion catches the tin ball at the periphery thereof, good contact can be achieved between the tin ball and the terminal.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: